jwurl

Switch to Holley efi and ditch the mefi system . You can use most if not all of your original sensors and injectors etc. the price of tuning your old system and sending it back and forth will be more than half the price of a Holley system. Went from mefi 3 to Holley efi on a non blown motor and the only thing I regret was not doing it that way the first time. Jeff wurl

zack

What are the part #'s you guys are talking about. What I was finding was the HP computer for @ $1100 then a $500 Holley harness, plus wiring and a tune. If that's the case I might be better off going with a built harness and computer from Eddie Young for $1850. Thanks for the help.

articfriends

Depending how handy you are with wiring you can buy a mefi4a ecu and harness from gm motorsports for 750 to 850$, you have to shop around and harness will need some work to git BUT i have retrofitted several of them onto various boat and car engine
http://www.gmpartsdirect.com/ignitio...7/?parent=1092
This is a example of the part number, not necessarily the best price out there, Smitty

zack

I looked at those, but I was told they would not work. Maybe that was because you have to splice all the sensors and parts?

hadleycat

Get ahold of Alex Haxby "Haxby Speed" on here for part numbers on the Holley for your motor. He is a distributor and can help you out. If you buy from Summit or Jegs you are on your own for tuning. Also search for the thread on here called " EFI for everyone" it has a ton of info related to your situation. It is a great read

zack

Will do thanks!

articfriends

Ramjet has similar intake to 500efi, alot of stuff will reach, what doesnt you solder and use heat shrink on. I bought 5 of those kits from local chevy dealer at same time, ben from precision retrofitted 2 of them on oso member cnc's awesome cats 1200hp blower motors. It all depends though on your skill level and tuning capability. I have zero interest in spending 4 thousand dollars on 2 holley efis just because they autotune when i can buy 2 mefi4as w harnesses for 1400$. Keep in mind they still need harnesses terminated and finished for every install and even though they have autotune features it still requires some tuning and fiddling. Mefiburn tuning software is like 700$. Ive made 1100 reliable hp using mefi.
On other hand, if you dont posses tuning skills and mefi IS complicated and you have to pay a third party for tunes or to tune your boat then buy the simplest system you can even if its a few thousand dollars more, youll be better off,Smitty

articfriends

On another note, you DEFINATELY want to have your injectors flowed and cleaned before boosting your motor, they are old and good chance a few flow low. Almost every set i flow and clean at my shop have at least one that flows 10 to 15 % high and one that flows 8+% low, Smitty

SB

Will his 454MPI's need the fuel rail mods ? I know the 502's do.

indysupra

http://www.jegs.com/i/Holley/510/550...FUtMDQod80sJtA